This project will investigate the development of infants' detection of intermodal invariants specifying gender. Three experiments are proposed. These concern infants' detection of invariant intermodal relations in bimodally-presented persons (MF) for a single pair of faces in one experiment, for a series of faces and voices in a second experiment, and for a series of faces accompanied by a single gender-specifying voice in a final experiment. Infants ranging in age from four to five months will be the subjects to determine whether infants this young are capable of sophisticated categorization based on intermodal invariant relations. The visual preference method will be used throughout. The project is concerned wit the devlopment of behavior as determined by psychological factors, particularly as it applies to how the developing infant abstracts and uss information given in intermodal events for understanding and structuring his/her environment.